﻿#include <iostream>
#include <thread>
#include <chrono>

int main() {
    using namespace std::chrono;
    auto now = steady_clock::now();
    auto wake_time = now + seconds(3); // 3秒后唤醒

    std::cout << "Sleeping until a specific time..." << std::endl;
    std::this_thread::sleep_until(wake_time); // 等到 wake_time
    std::cout << "Woke up after 3 seconds." << std::endl;

    return 0;
}
